1. Field of the Invention
The present invention relates to an ink set for ink-jet recording, an ink-jet recording method and an ink-jet recording apparatus.
2. Description of the Related Art
An ink-jet recording method for ejecting a liquid or molten solid ink from an ink-ejection port such as a nozzle, slit or porous film has been used for many printers since the apparatus used for this method is small in size and inexpensive. A piezoelectric ink-jet recording method for ejecting the ink by taking advantage of deformation of a piezoelectric element or a thermal ink-jet recording method taking advantage of boiling of the ink by thermal energy have been often utilized among various ink-jet recording methods from the view point of high resolution and high printing speed. Further, an ink-jet printer is able to print not only on paper sheets such as plain paper and ink-jet printing paper, but also on films such as OHP sheets and clothes.
High speed printing and high image quality are important issues in the technical field of ink-jet printers at present. Japanese Patent No. 2,667,401 proposes an image forming method for satisfying high speed printing and high image quality together by allowing a liquid (c)ontaining a cationic group-bearing compound to adhere on a recording medium, followed by allowing an ink containing an anionic dye to adhere immediately after the liquid permeates into and remains in the recording medium.
U.S. Pat. No. 5,679,143 proposes an ink set comprising a first ink and a second ink having different pH values from each other for preventing bleeding between the two inks by allowing the ink components to coagulate when the first ink contacts the second ink.
However, in the above methods when the first ink and the second ink are stored in a common maintenance unit, these are cases where the inks are coagulated in the maintenance unit and reliability of the maintenance unit cannot be ensured.
Therefore, it has not been possible to satisfy optical density, feathering, intercolor bleeding, drying time and reliability of the maintenance unit at the same time by the conventional methods.